In the conventional thin-film forming apparatus, the printing preparatory works, such as mounting/dismounting of the elastic plate, and wiping out of the intaglio roll and the doctor blade, are carried out by the operator by hand, before the printing operation. These works will be concretely described below.
In the thin-film forming apparatus shown in FIG. 31, in order to mount the elastic plate to the barrel of the printing roll, marks for positioning provided in plural places of the elastic plate and reference marks provided in plural places of the barrel of the printing roll are first positioned by the operator's hand(s) and the eyes of the operator, and the elastic plate is stretched by the operator's hand(s) to be wound around the barrel of the printing roll. Afterwards, elastic plate holders which are mounted on both ends of the elastic plate are fixed by the operator's hand(s), by hooking them to chuck means mounted on the barrel of the printing roll.
Then, the ink is filled into the plurality of ink cells of the intaglio roll by an ink supply means, transferred from the intaglio roll to the elastic plate of the printing roll, and transferred from the printing roll to the to-be-printed material which is fixed on the printing table to carry out the printing.
Furthermore, after the printing is completed, in order to dismount the elastic plate from the barrel of the printing roll, the elastic plate holders mounted on both ends of the elastic plate are dismounted by the operator's hand(s) from the chuck means on the barrel of the printing roll.
Furthermore, in the conventional thin-film forming apparatus, alloy the ink in the ink cells of the intaglio roll is not always transferred to the printing roll, and a part of the ink remains in the ink cells of the intaglio roll. If the residual ink is left as is, the residual ink will dry or stiffen to form an ink solid, and the ink solid adheres to the inner part of the ink cells. If the intaglio roll is used as is, the adhered ink is redissolved in new ink, or the ink solid drops out to be mixed in the new ink supplied to the intaglio roll, thereby resulting in deteriorated ink being used for the printing. Furthermore, since the ink adhered to the ink cells decreases the volume of the ink cells, the transferred amount of the ink to the printing roll is decreased by that amount.
Therefore, conventionally, the residual ink in the ink cells of the intaglio roll is wiped out, which is done all by the operator's hand(s). Namely, a wiper is first saturated with solvent which dissolves the ink, and pressed by the operator's hand against the barrel surface of the intaglio roll with a predetermined contact pressure, and is moved along the axial direction of the intaglio roll, while rotating the intaglio roll in the state that the wiper is pressed against it.
Then, in order to remove the solvent which is left on the barrel surface of the intaglio roll, the intaglio roll is dried. Namely, a gas ejecting means which ejects gas for drying the intaglio roll is first placed by the operator's hand(s) so that there is a predetermined distance between the gas ejecting means and the barrel surface of the intaglio roll, and while ejecting the gas to the barrel surface of the rotating intaglio roll, the gas ejecting means is moved by the operator's hand(s) along the axial direction of the intaglio roll while rotating the intaglio roll.
Then, the ink is filled into the plurality of ink cells of the intaglio roll by the ink supply means, transferred from the intaglio roll to the elastic plate of the printing roll, and transferred from the printing roll to the to-be-printed material which is fixed on the printing table to carry out the printing.
Furthermore, the doctor blade is a plate-shaped body, and mounted to the doctor blade-supporting rod (see FIG. 27). Since the doctor blade has a function to scrape off ink on the barrel surface of the rotating intaglio roll, and to ensure and measure the filling of the ink into the ink cells of the intaglio roll, if the doctor blade to which the ink has adhered is left as is, the adhered ink will dry or stiffen to become an ink solid, and the ink solid adheres to the doctor blade. If the ink-adhered doctor blade is used, the adhered ink is redissolved in new ink, or the ink solid drops out to be mixed in the new ink supplied to the intaglio roll, thereby resulting in deteriorated ink being used for the printing. Furthermore, since the tip of the doctor blade becomes uneven due to the adhered ink, the scraping-off of unnecessary ink cannot be done evenly, and it becomes difficult to secure the filling into the all of ink cells of the intaglio roll and measuring the ink amount.
Therefore, conventionally, the ink adhered to the doctor blade is wiped out, which is done all by the operator's hand(s). Namely, the wiper, first saturated with solvent, is held in the operator's hand(s) to hold the doctor blade between them with a predetermined contact pressure, and are moved along the longitudinal direction of the doctor blade such that the doctor blade is put therebetween. Then, in order to remove the solvent which stays behind on the doctor blade, the doctor blade is dried by the operator's hand(s). Namely, a gas ejecting means which ejects gas for drying the doctor blade is placed by the operator's hand(s) so that there is a predetermined distance between the gas ejecting means and the doctor blade, and while ejecting the gas to the doctor blade, the gas ejecting means is moved by the operator's hand(s) along the longitudinal direction of the doctor blade.
Then, the ink is filled into the plurality of ink cells of the intaglio roll by the ink supply means, transferred from the intaglio roll to the elastic plate of the printing roll, and transferred from the printing roll to the to-be-printed material which is fixed on the printing table to carry out the printing.
However, there are some problems described below in the conventional thin-film forming apparatus:
(1) Since all the works, such as positioning of the elastic plate and the barrel of the printing roll, stretching of the elastic plate, hooking to the chuck means, mounting/dismounting of the elastic plate to the barrel of the printing roll, wiping and drying of the intaglio roll, and wiping and drying of the doctor blade are performed by the operator's hand(s), and thereafter, the printing is carried out, the efficiency to form the thin-film is very low.
(2) Since lots of people go in and out in order to mount the elastic plate to the barrel of the printing roll, to wipe out the intaglio roll, and to wipe out the doctor blade, lots of dust is raised from the people themselves, the clothing thereof, and the grounds, and thus the cleanness in the surroundings is deteriorated. Also, since the elastic plate is held by the operator's hand(s), there is a case where the elastic plate is held by dirty oily hands. Thus, dust, dirt and oils adhere to the elastic plate to make it dirty.
When ink is transferred from the intaglio roll to such an elastic plate, dust, dirt and oils are mixed in the ink, and thus, the ink tends to have foreign substances mixed therein or is deteriorated. Accordingly, when a macromolecular thin-film such as a liquid crystal orientation film or the like is formed by using such ink, there are caused such problems are caused in that the functions of the thin-film are deteriorated because the insulating property is deteriorated, unevenness in the film thickness or in the orientation occurs, and a part of the film is broken.
(3) Since the elastic plate is wound around the barrel of the printing roll, while stretching it by the operator's hand(s), it is difficult to make the tension have a predetermined magnitude and a predetermined direction as applied along the whole width of the elastic plate, when the elastic plate is wound around the barrel of the printing roll. If much attention is not given to carry out the work, the elastic plate might be sometimes wound around the barrel of the printing roll such that an excessive tension or a slackening tension is applied to the elastic plate to be wound which cannot be corrected. As a result, there might be a case where the elastic plate is mounted to the barrel of the printing roll such that an excessive tension is applied to the elastic plate or such that the elastic plate has wrinkles or waves.
When the intaglio roll is brought into contact with the elastic plate in such a state, the contact pressure between the intaglio roll and the elastic plate and the contact pressure between the elastic plate and the to-be-printed material become uneven, and there are places having uneven transfer volume in the to-be-printed material, and a thin-film having an uniform film thickness cannot be formed on the to-be-printed material. When an attempt is made to mount an elastic plate on the printing roll by the operator's hand(s) so as not to cause these defects, even an expert needs a lot of time, and the efficiency to form a thin-film is decreased.
(4) Since the intaglio roll is wiped out by pressing a wiper held by the operator's hand(s) against the intaglio roll, it is quite difficult to press the wiper against the intaglio roll with a predetermined contact pressure and to maintain the predetermined contact pressure, while moving the wiper in the axial direction of the intaglio roll, and the contact pressure becomes too strong or too weak. As a result, there are places where it is sufficiently wiped out and where it is insufficiently wiped out and the residual ink adhered to the ink cells cannot be removed sufficiently. It is also impossible to uniformly wipe out the barrel surface of the intaglio roll.
When ink is supplied to the intaglio roll which has not been sufficiently wiped out, the ink adhered to the intaglio roll is mixed with ink newly supplied to the intaglio roll, and thus a different kind of ink is mixed every time when the ink is exchanged to another kind. Also, since the adhered ink is left in the ink cells without being transferred to the printing roll, the amount of ink transferred to the printing roll becomes less by that amount, and thus, a thin-film having a sufficient film thickness cannot be formed on the to-be-printed material.
Furthermore, if the ink is not wiped out sufficiently and uniformly, some ink cells have enough ink and some have less ink, and thus the amount of ink transferred to the printing roll becomes uneven, and the film thickness becomes uneven. Therefore, for example, when a macromolecular thin-film pattern such as a liquid crystal orientation film is formed, problems are caused in that the film thickness becomes uneven to cause unevenness in the display, and the functions of the thin-film are deteriorated.
(5) Since the drying of the intaglio roll is carried out by holding the gas ejecting means by the operator's hand(s), it is quite difficult to maintain a predetermined distance between the gas ejecting means and the barrel surface of the intaglio roll, while moving the gas ejecting means in the axial direction of the intaglio roll, and the distance tends to become too large or too small. As a result, some places are dried sufficiently and some are not, and the barrel surface of the intaglio roll cannot be dried uniformly.
When ink is supplied to the intaglio roll which has not been uniformly dried, the solvent used for wiping is mixed in new ink supplied to the intaglio roll as an impurity. Therefore, in the case where a macromolecular thin-film pattern, such as a liquid crystal orientation film, is formed by using such ink, problems are caused in that the insulating property is deteriorated and the functions of the thin-film are deteriorated due to the unevenness in the film thickness and in the orientation.
(6) When a doctor blade made of plastic is used, if a hard substance such as a nail of a finger hits the tip of the doctor blade during the wiping operation by the operator's hand(s), the tip of the doctor blade becomes uneven so that the scraping-off of unnecessary ink is unevenly done, and it becomes difficult to secure the filling and measuring into all the ink cells of the intaglio roll.
(7) Since the wiping is carried out by holding a doctor blade by the wiper held by the operator's hand(s), it is quite difficult to press the wiper against the tip of the doctor blade with a predetermined contact pressure and to maintain the predetermined contact pressure while moving the wiper in the longitudinal direction of the doctor blade, and the contact pressure becomes too strong or too weak. As a result, the tip of the doctor blade and the wiper part from each other so that the tip of the doctor blade cannot be wiped out, or the tip of the doctor blade and the wiper contact each other too strongly to break the wiper, and thus the workability is deteriorated. Also, it is quite dangerous in that a hand of the operator may rub against the tip of the doctor blade to get injured.
(8) Since wiping is carried out by holding the doctor blade between the wiper held by the operator's hand(s), it is quite difficult to hold the doctor blade by the wiper with a predetermined holding pressure and to maintain the predetermined holding pressure while moving the wiper in the longitudinal direction of the doctor blade, and the holding pressure becomes too strong or too weak. As a result, some places are wiped out sufficiently and some are not, and the residual ink adhered to the doctor blade cannot be removed sufficiently. Also, the doctor blade cannot be wiped out uniformly.
When ink is filled and the ink amount is measured by a doctor blade which has not been sufficiently wiped out, the ink adhered to the doctor blade is mixed with ink newly supplied to the intaglio roll, and thus a different kind of ink is mixed every time when the ink is exchanged to another kind. Also, when the tip of the doctor blade becomes uneven, the scraping-off of unnecessary ink is unevenly done, and it becomes difficult to secure the filling and measuring into all the ink cells of the intaglio roll.
Furthermore, if the ink is not wiped out sufficiently and uniformly, the tip of the doctor blade becomes uneven due to the adhered ink, and thus some ink cells have enough ink and some have less ink, which causes an unevenness in the amount of the ink in the ink cells, and the film thickness becomes uneven. Therefore, for example, when a macromolecular thin-film pattern such as a liquid crystal orientation film is formed, problems are caused in that the film thickness becomes uneven to cause an unevenness in the display and the functions of the thin-film are deteriorated.
(9) Since the drying of a doctor blade is carried out by holding a gas ejecting means for drying by the hand of an operator, it is quite difficult to maintain a predetermined distance between the gas ejecting means and the doctor blade while moving the gas ejecting means in the longitudinal direction of the doctor blade, and the distance tends to become large or small. As a result, some places are dried sufficiently and some are not, and thus the doctor blade cannot be dried uniformly.
When a doctor blade which has not been uniformly dried is used, solvent used for wiping is mixed in new ink supplied to the intaglio roll. Therefore, in the case where a macromolecular thin-film pattern, such as a liquid crystal orientation film, is formed by using such an ink, problems are caused in that the insulating property is deteriorated and the functions of the thin-film are deteriorated due to the unevenness in the film thickness and in the orientation.
Therefore, the object of the present invention is to overcome the above-mentioned problems, and to provide a thin-film forming apparatus and a thin-film forming method which can improve the functions of the thin-film and the working efficiency, by automating the printing preparatory works without using operator's hands.